<!DOCTYPE html>
<html>
	<head>
		<meta charset="utf-8" />
		<title></title>
		<style>
			
			#txt{
				width: 600px;
				text-align: center;
				margin: auto;
				color: red;
			}
			
			
		</style>
		
	</head>
	
	
	
	<body>
		
		<div id = "txt"></div>
		
		
		
		
		<script>
				
			// for (var k < 0; k < 10; k++){
				
				
			// 	for (var i = -1; i < k; i++ ){
			// 		document.write("☆");
			// 	}
			// 	document.write("<br/>");
				
			// }
			
			//1. j = 0
			//2. j < 10 0
			//3. i = 0  0  0
			//4. i < j  0  0
			//5. <br/>
			//6. j++    1
			//7. j < 10 1  
			//8. i = 0  1  0
			//9. i < j  1  0
			//10.         ☆
			//11.i++    1  1
			//12.i < j  
			//13.      <br/>
			//14.j++    2
			//15.
			 
			
			// for (var k = 10; k > 0; k--){
				
				
			// 	for (var i = 0; i < k; i++){
			// 		document.write("☆");
			// 	}
			// 	document.write("<br/>");
				
			// }
			//i += 2  ->   i = i + 2
			
				
			
			for (var k = 0; k < 30; k++){
				
				
				for (var i = 0; i < k; i++){
					document.getElementById("txt").innerHTML += ("☆");
				}
				document.getElementById("txt").innerHTML += ("<br/>");
				
			}
			
			
		</script>
		
		
	</body>
</html>
